1. Do not share user accounts! Any account that is shared by another person will be blocked and closed. This means: we will close not only the account that is shared, but also the main account of the user who uses another person's account. We have the ability to detect account sharing, so please do not try to cheat the system. This action will take place on 04/18/2023. Read all forum rules.
    Dismiss Notice
  2. For downloading SimTools plugins you need a Download Package. Get it with virtual coins that you receive for forum activity or Buy Download Package - We have a zero Spam tolerance so read our forum rules first.

    Buy Now a Download Plan!
  3. Do not try to cheat our system and do not post an unnecessary amount of useless posts only to earn credits here. We have a zero spam tolerance policy and this will cause a ban of your user account. Otherwise we wish you a pleasant stay here! Read the forum rules
  4. We have a few rules which you need to read and accept before posting anything here! Following these rules will keep the forum clean and your stay pleasant. Do not follow these rules can lead to permanent exclusion from this website: Read the forum rules.
    Are you a company? Read our company rules

wannabeaflyers 6 DOF with 24V DC gearmotor

Discussion in 'DIY Motion Simulator Projects' started by wannabeaflyer, Feb 2, 2014.

  1. wannabeaflyer2

    wannabeaflyer2 Well-Known Member

    Joined:
    Jun 12, 2015
    Messages:
    724
    Location:
    london uk
    Balance:
    8,286Coins
    Ratings:
    +950 / 7 / -0
    My Motion Simulator:
    2DOF, Arduino, Motion platform, 6DOF
    She Lives LOL and Baby's Kicking But LOL not weight tested yet so this may well turn out to be the biggest model sim yet :) , a little bit excited to see the old girl go through the motions , Massive amount of refinements to make but the basics seem to be in place , Stop laughing guys and have a look see :)
    • Like Like x 4
    • Winner Winner x 1
  2. wannabeaflyer2

    wannabeaflyer2 Well-Known Member

    Joined:
    Jun 12, 2015
    Messages:
    724
    Location:
    london uk
    Balance:
    8,286Coins
    Ratings:
    +950 / 7 / -0
    My Motion Simulator:
    2DOF, Arduino, Motion platform, 6DOF
    Gonna Sit Back take stock and make some changes, Main lesson it seems so far is Boo Hoo Me, thinks the Actuators may not be man enough (Bugger) But to be honest i Knew these were the things i'd Find out ( Wormdrives are def the way) These Motors may well be fine under power But i noticed when they are not enegrised they will Backdrive with Heavy weight on platform ( That'll be my Lard arse Butt Then) I Need to get rid of a number of Finger Pinch ( Chop it Off ) Points so the next iteration will be about these Mod's , The 3 Controller/ Kangeroo Units are exposed under the Platform at the Moment Because of my attempt and a Modular design ( to make it easy to move and re-assemble But Now like the Idea of a Control Box Enclosure ( WIP ) , She seems Fast enough for Flight sim using Ians BFF software so the Next Challenge will be To Use Simtools ( with Car Racing Sim ) , Thanks to you guys i believe i have managed to Get the autotune almost Right , and My Optical Encoders have arrived so i'll attempt interfacing these to the Kangeroo to compare results with the 180° Hall Sensors ..
    Given where i am with this Project ( 1st time design ) the Range of movement may need tweaking as im sure the angles should be greater . That's why i believe we need a section for 6 DOF Plans with Possible Scaleable Baseline key dimensions for experimenters ... i'll still put these plans up for any one interested but the Mk2 will be here soon , Lessons being learnt all the Time LOL Main One READ THE BLOODY MANUALS LOL ( That's me shouting at Me . don't just look at em ( Like dofuss here). in my case all the info was there, it was more a case of me looking but not reading if you get my drift .. on the 2nd and 3rd read through the penny dropped and the Eureka moment arrived . Cheers Guys getting there and having a fun journey
  3. telfel

    telfel Active Member

    Joined:
    Feb 16, 2011
    Messages:
    170
    Balance:
    4,735Coins
    Ratings:
    +118 / 3 / -0
    Hi you can set motors to be electrically braked in the describe tool, where are you going to fix the encoders
    motor armature or gearbox output?

    regards Terry
  4. wannabeaflyer2

    wannabeaflyer2 Well-Known Member

    Joined:
    Jun 12, 2015
    Messages:
    724
    Location:
    london uk
    Balance:
    8,286Coins
    Ratings:
    +950 / 7 / -0
    My Motion Simulator:
    2DOF, Arduino, Motion platform, 6DOF
    Hi Terry , I removed the Electric Brake form each motor but Being a hoarder luckily i think i still have them, The New DE Sabertooth 2x32 has the facility to switch the brake on and off , but i was worried the frequency at which this will occur in the sim would be a problem , I am about the ask the DE Guys if its possible to use the brakes in a simulator like mine , if the answer is favourable then i will swap oyt the 2x25's for 2 new 2x32s to make use of this feateure
    The Encoder were going to be direct replacements for the 180° Hall sensors but may have an issue with the Gear box Backlash :) all these types of Gearboxes will have some Backlash so its a question on how it will affect the sensor Position output ( jitter etc) . Dammm Your Good , I Just realised that maybe i can mount the encoder on the Brake shaft extention on the back of the motor and so get rid of any backlash Problems ,,,Ohhh Now thats a great idea
    Been advised that the actuator arms need to be typically 90° with respect to the Connection Rod and the Top Frame to get the best out of movement available so that's the next Mod .. Thanks for Posting Terry will keep you guys updated as the learning curve steepens :)
  5. telfel

    telfel Active Member

    Joined:
    Feb 16, 2011
    Messages:
    170
    Balance:
    4,735Coins
    Ratings:
    +118 / 3 / -0
    Hi
    I think the system can apply a braking force by applying power to the windings at the same time, so you dont need the brake windings.

    regards Terry
    • Useful Useful x 1
  6. telfel

    telfel Active Member

    Joined:
    Feb 16, 2011
    Messages:
    170
    Balance:
    4,735Coins
    Ratings:
    +118 / 3 / -0
    Hi
    I had mounted an optical encoder on the armature shaft as a test compared to a hall sensor on the back of the gearbox output shaft, the output waveform in the describe software was much cleaner and the deadband could be reduced.

    How many clicks will you get from your encoders, if mounted on the back gearbox shaft you may get less accurate output, for best results I think you need to mount to read the motor armature. you may also need to rig up a microswitch to give you a home position, if you use two, one for min and max position that will give you a safety cutout.

    regards Terry
    • Like Like x 1
  7. telfel

    telfel Active Member

    Joined:
    Feb 16, 2011
    Messages:
    170
    Balance:
    4,735Coins
    Ratings:
    +118 / 3 / -0
    Hi

    Yes from old RC servo setup days, the push rod should be at 90 deg to the crank arm at the mid position, this will give the most sensitive movement at the mid position, also for a linear input you get a non linear movement the further the crank arm moves away from the mid position.
    At 90 deg crank arm from mid position you get no movement at the platform end, go past 90 deg and you get the movement to reverse.

    regards Terry
    • Like Like x 1
    • Useful Useful x 1
  8. wannabeaflyer2

    wannabeaflyer2 Well-Known Member

    Joined:
    Jun 12, 2015
    Messages:
    724
    Location:
    london uk
    Balance:
    8,286Coins
    Ratings:
    +950 / 7 / -0
    My Motion Simulator:
    2DOF, Arduino, Motion platform, 6DOF
    Hi Terry Once again thanks for taking the time to give this Very Useful Info , My Optical Encoders are the 600 ppr type and i was going to do a straight hall sensor swap on my test motor / Gearbox , but you got me thinking about using the Motor Shaft for direct / No Backlash readings so i'm going to try that setup , will keep you all posted, i read somewhere that the Kangeroo read Rate should be capable of keeping up with the encoder so this would be a great option.. Cheers :)
    I'm still working on my adjustable limit switch setup and was hoping to use one of the 2 Limit switches per Actuator ( min / Max Over travel detection) as configured by Describe Utility as the Homing switch for the encoders , over the next few days if i can stop tweaking the platform , i'll give it a whirl and see how i get on ..:)
  9. SeatTime

    SeatTime Well-Known Member

    Joined:
    Dec 27, 2013
    Messages:
    2,574
    Occupation:
    Retired
    Location:
    Brisbane Australia
    Balance:
    28,370Coins
    Ratings:
    +2,844 / 38 / -0
    My Motion Simulator:
    AC motor, Motion platform
    Looks great :thumbs, even if it won't support a rig+passenger, you have certainly learnt a lot to enable you to scale it up. It just unfortunate that big motors and high torque gearboxes are so expensive for your average DIYer.
  10. Kirk

    Kirk Member

    Joined:
    May 19, 2014
    Messages:
    91
    Occupation:
    Sr Software Engineer
    Location:
    Texas
    Balance:
    15,087Coins
    Ratings:
    +114 / 2 / -0
    My Motion Simulator:
    2DOF, DC motor
    Didn't see the video until just now, very cool, and very responsive.

    I believe your motors will be fine, especially if you shortened the levers on the motors a tad, and implemented the 12V mag breaks for the motors.

    Reducing the length of the arms won't reduce it's responsiveness, just the total travel distance. I wouldn't reduce it until you've weight tested what you have to determine how much weight it can move before the motors stall. Once you know that, assuming you needed to shorten them, you'll know the total length to make them (based on rig weight and your weight, vs. the weight they stalled at).

    I would also measure the current it stalled at, and verify you are not encountering a limitation of your controller. You can do this by attaching directly to power and get it to try and lift a heavy object, the current should be what you measured with the controller. If not, you might want bigger controllers, but much cheaper than 6 new mega-beefy motors.

    When testing stall current, you don't want to leave the motor in a stalled state for any period of time, just long enough to get your reading.
  11. SilentChill

    SilentChill Problem Maker

    Joined:
    Jul 19, 2014
    Messages:
    2,619
    Occupation:
    Railway Maintenance
    Location:
    Morecambe, Lancashire, England
    Balance:
    20,396Coins
    Ratings:
    +3,480 / 34 / -0
    My Motion Simulator:
    DC motor, Arduino, Motion platform, 6DOF
    @wannabeaflyer how long are you arms CTC ? I have had to lower mine to 50mm and i still get plenty of movement over heating is my problem . I started at 100mm and they moved but after 10 minutes the motors were nearly too hot to touch
  12. wannabeaflyer2

    wannabeaflyer2 Well-Known Member

    Joined:
    Jun 12, 2015
    Messages:
    724
    Location:
    london uk
    Balance:
    8,286Coins
    Ratings:
    +950 / 7 / -0
    My Motion Simulator:
    2DOF, Arduino, Motion platform, 6DOF
    Hi Guys I'm very much encouraged by the feedback im getting , this place is a goldmine of helpful members and great ideas, so it's just a case of me riding the wave that you guys created,
    Hi Silentchill My Actuator arms are 100mm ctc but have drilled holes for 75 and 50mm just in case, was not sure about how much I would need to get the desired Angles etc so it great to know that I can drop this down to maybe 50 ( which in turn means more torque ) see your rig chuck you around so even at 50 mm CTC that looked sweet to me ,
    Hi Kirk once again cheers for the input its all good stuff as far as this wannabe goes , I connected a Current meter & Shunt to the rig but strange upon strange it only registered less than 10 Amps ???? with me being chucked all over ad hanging on for dear life so im thinking that's not a true figure ( my dodgy wiring again I suspect)in saying that , I don't think that im even close to tripping the current limit on the sabertooth ,with the rig as it stand at the moment, but your dead right I need to load these babies up to see their stall current, luckily the Sabertooth controllers have inbuilt current overload protection so all good stuff Thanks keep em coming its all shared with the other members of the forum ..

    Ok guys latest info , still a lot of fine tuning to do but having stuck my big butt on the platform and had it throw me around like a bucking bronco , she may well be ok as a seat mover with my all up weight , the fly in the ointment is that every now and then one of the motors will throw up Kangeroo Error message indicating the motor controller has detected an error ( generally position related I,e gone past min level) this again may be to do with the Tuning as I purposely did not tune the actuators with the platform fully loaded ( at this part of the testing stage) as I wanted to get the basics running first be fore revisiting this operation.
    The Autotune is a wee bit vicious on the mechanics but then again if built right this should not be an issue.. ( at the moment its at basic assembly stage so needs beefing up) .. I.m happy with the fact that im learning a bit more each time I play with the system and the comms problems have gone , im able to switch from BFF software to Describe and back at will and having sat on it while its moving , sorta shows there's potential there, the Motors say rated at 3 Amps each, and as they are not all on at the same time , maybe that explains the low current ( still suspect my dodgy connections though ) ,
    I did set the describe function to hold power when off but they still back-drive when a heavyweight( i.e lard arse here) is applied , again I suspect I have not activated the right control function for that, so more reading required... Cheers Guys for the tips and the interest , as per usual i'll bore ya with the details as and when I get more play time LOL :)
    • Like Like x 1
  13. wannabeaflyer2

    wannabeaflyer2 Well-Known Member

    Joined:
    Jun 12, 2015
    Messages:
    724
    Location:
    london uk
    Balance:
    8,286Coins
    Ratings:
    +950 / 7 / -0
    My Motion Simulator:
    2DOF, Arduino, Motion platform, 6DOF
    D'oh as Homer simpson would say , Just watched a video I made to see what the current meter was registering under load and
    noticed that the peaks went up to 55 -85 amps every now and then , I think I will need to create a Ardunino routing to capture the info so that I can see it on paper as its changing to fast for me to give you guys accurate info ,.. any other suggestion to log the amps drawn values from the shunt would be great ..cheers
  14. BlazinH

    BlazinH Well-Known Member

    Joined:
    Oct 19, 2013
    Messages:
    2,145
    Location:
    Oklahoma City, USA
    Balance:
    16,568Coins
    Ratings:
    +1,831 / 32 / -1
    Use this same tip if the tuning process is too vicious!

    If you use a multimeter that has a max hold feature it will hold and show the highest obtained reading. Or you could get a multimeter that logs to your PC.
    • Like Like x 1
  15. wannabeaflyer2

    wannabeaflyer2 Well-Known Member

    Joined:
    Jun 12, 2015
    Messages:
    724
    Location:
    london uk
    Balance:
    8,286Coins
    Ratings:
    +950 / 7 / -0
    My Motion Simulator:
    2DOF, Arduino, Motion platform, 6DOF
    Hi BlazingH , Will Try borrow a Dc meter with Max Hold to see if i can catch that figure once again thanks for the Tip :)
  16. Blugreen

    Blugreen New Member

    Joined:
    Oct 5, 2014
    Messages:
    13
    Balance:
    477Coins
    Ratings:
    +25 / 0 / -0
    My Motion Simulator:
    6DOF
    Watching this with interest.
  17. tomkil192

    tomkil192 Member

    Joined:
    Jun 25, 2015
    Messages:
    81
    Location:
    Uk. London
    Balance:
    - 25Coins
    Ratings:
    +26 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    Hi wannabeaflyer. Great project and lots of improvmens. Well done. Would you recomend wheelchair motors for 2 dof platform? Im about to build my first one and they seams to be the cheapest option.
  18. wannabeaflyer2

    wannabeaflyer2 Well-Known Member

    Joined:
    Jun 12, 2015
    Messages:
    724
    Location:
    london uk
    Balance:
    8,286Coins
    Ratings:
    +950 / 7 / -0
    My Motion Simulator:
    2DOF, Arduino, Motion platform, 6DOF
    Hi Tomkil192 I have 2 projects on the go at the moment my boys 2dof uses the same wheelchair/ gearbox units im using on my 6DOF project the seat is built and the electronics tested at basic level , so im sure these motor will be strong enough to easily throw a seat mover around and Possibly a whole rig if its balanced correctly ... my only doubt at the moment is they may well backdrive because they are not wormgear drive type gearboxes , that in itself should not be a problem with a balanced seat mover but that's my newbie Thought , Their are guys here that will be able to give you a better answer, I got these units at a great price so im really just trying to get some use for them on the basis that if wiper motor can allow such awesome sims then these babies should be ok ( Don't Quote me on that though :) ) .. Cheers For the interest
  19. wannabeaflyer2

    wannabeaflyer2 Well-Known Member

    Joined:
    Jun 12, 2015
    Messages:
    724
    Location:
    london uk
    Balance:
    8,286Coins
    Ratings:
    +950 / 7 / -0
    My Motion Simulator:
    2DOF, Arduino, Motion platform, 6DOF
    Hi Guys Just an minor update , Done some basic test now and it seems under load My Electric wheel chair motor/gearbox units will draw 20-25 amps possibly more when loaded up ,but then again with my setup I don't think all the motors are powered up, if no position command is sent , so that 20 -25 was only what the amp meter in the battery supply rail saw , Not the most scientific method used but at least it gave me an indication as to whether or not I was hitting the Current limit of the Sabertooth Controllers. The biggest issue I currently face is the fact that these motors can be back-driven if not powered (Bummmerr or what, but in my heart I knew that would be the case as they are not Wormgear type gearboxes) ,
    You guys have posted some options which I will try to implement , on a whole im still happy with the progress , setback toughen up the character I think they say ( at this stage I need to believe that lol :) ) .. so all is not lost guys I think if I crack this issue of getting the motors to hold position then a massive step will be made.. as I always say hang in there guys and watch this space :) Cheers Crew
    • Like Like x 1
  20. tomkil192

    tomkil192 Member

    Joined:
    Jun 25, 2015
    Messages:
    81
    Location:
    Uk. London
    Balance:
    - 25Coins
    Ratings:
    +26 / 0 / -0
    My Motion Simulator:
    2DOF, DC motor, Arduino
    @wannabeaflyer thanks for reply. I will go for worm motor due to the back driven fact on the wheel chair ones but i wish you the best with your project. Your new baby looks very good.
    The only way to stop the motors driving back under load is the break what you removed. we use them all day long on SEW motors for holding the break. It might be annoying clicking sound because it will be breaking every few seconds but it will work.